Arthritis & Rheumatism, Volume 63,
November 2011 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Chicago, Illinois November 4-9, 2011.

Diffusion Tensor and Perfusion Magnetic Resonance Imaging Delineates Microstructural Changes of Inflammation and Differentiates Between Tuberculosis and Chronic Inflammatory Arthritis.

Agarwal¹, Vikas, Awasthi², Rishi, Tripathi³, Deepak, Agrawal³, Vinita, Singh Rathore⁴, Ram Kishore, Sahoo⁴, Prativa, Sharma⁵, Kusum

Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Lucknow, India
Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India,, Lucknow, India
Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Lucknow, India
Indian Institute of Technology, Kanpur, India
Postgraduate Institute of Medical Education and Research, Chandigarh, India

Background/Purpose:

Conventional MRI does not differentiate between infective and non-infective chronic inflammatory arthritis. Synovial histology and culture are the only means to differentiate between these two. Chronic inflammation is characterized by cellular infiltration and increased vascularity. We hypothesize that Diffusion tensor imaging (DTI), a non-contrast MRI technique, delineates synovial inflammation. DTI derived metrics [fractional anisotropy (FA), mean diffusivity (MD), linear anisotropy (CL), planar anisotropy (CP) and cylindrical isotropy (CS)] and perfusion parameters [blood flow (BF) and blood volume (BV)] assess cellular infiltration and vascularity, respectively, in inflamed synovium. Also, increased inflammation during infection should lead to greater variation in DTI and perfusion parameters that should differentiate between the two conditions.

Methods:

Patients with knee arthritis (>3 months duration) underwent conventional and DTI (3T scanner) followed by arthroscopic biopsy. Synovial tissue was subjected to histopathology, immunohistochemistry (IHC), and culture and multiplex PCR for Mycobacterium tuberculosis. In-house developed software was used to process DTI and perfusion data. Pearson correlation coefficient was used to evaluate correlation between DTI and perfusion and IHC parameters. Independent samples t-test was used to compare parameters between tubercular and non-tubercular patients. Discriminant analysis was done to ascertain imaging parameters discriminant of tuberculosis.

Results:

There were 41 patients (mean age 38 years, [range 18–75], 27 male). Ten patients had tuberculosis and rest had; chronic monoarthritis (n=11), undifferentiated spondyloarthropathy (n=12), osteoarthritis (n=3), reactive (n=2) and rheumatoid, juvenile idiopathic and lepra reaction one each. There was significant correlation between the DTI, perfusion and IHC parameters (Table-1). DTI, perfusion and IHC parameters were significantly different in the tubercular as compared to the non-tubercular group (Table-2). FA and blood volume were 100% sensitive and specific in discriminating and predicting tuberculosis.

Table 1. Correlation coefficient (R) between DTI, Perfusion and IHC markers (n=41)

Parameter	CD3	CD4	CD8	CD68	Total cells	CD34	CD54	TNFa	IL-1b
FA	0.59*	0.64*	0.46^@	0.63*	0.77*	0.84*	0.45^@	0.69*	0.67*
MD	-0.41^@	-0.39^#	-0.28	-0.32^#	-0.46^@	-0.49^@	-0.27	-0.3	-0.48^#
CL	0.44^@	0.53*	0.32^#	0.36^#	0.49^@	0.62*	0.18	0.38^#	0.54*
CP	0.36^#	0.24	0.33^#	0.21	0.26	0.17	0.05	0.33^#	0.13
CS	-0.3	-0.44^@	-0.18	-0.28	-0.42^@	-0.51^@	-0.56*	-0.41^@	-0.42^@
Blood flow	0.39^@	0.42^@	0.23	0.49^@	0.58*	0.73*	0.4^@	0.58*	0.55*
Blood volume	0.59*	0.66*	0.53*	0.53*	0.75*	0.90*	0.50^@	0.64*	0.77*
*p<0.001,@p<0.01,#p<0.05

Table 2. Comparison of DTI, perfusion and IHC markers between tubercular and non-tubercular groups

Parameters	Tuberculosis (n=10) Mean ± SD	Non-tubercular (n=31) Mean ± SD	P value
DTI
FA	0.27 ± 0.01	0.21 ± 0.00	<0.001
MD	1.01 ± 0.04	1.6 ± 0.54	0.002
CL	0.08 ± 0.02	0.05 ± 0.02	<0.001
CP	0.16 ± 0.04	0.14 ± 0.05	0.27
CS	0.69 ± 0.05	0.76 ± 0.03	<0.001
Perfusion
BV	16.24 ± 1.99	3.23 ± 2.22	<0.001
BF	161.26 ± 16.9	99.22 ± 36.55	<0.001
IHC
CD3	193.40 ± 61.99	112.87 ± 39.56	<0.001
CD4	97.80 ± 33.80	48.03 ± 18.40	<0.001
CD8	72.80 ± 17.51	42.90 ± 25.29	0.001
CD68	253.90 ± 64.10	157.94 ± 70.72	<0.001
CD34	194.60 ± 51.73	41.42 ± 18.35	<0.001
CD54	90.30 ± 62.34	33.71 ± 13.63	<0.001
TNFa	33.10 ± 7.90	18.77 ± 7.94	<0.001
IL-1b	55.90 ± 14.50	21.30 ± 11.93	<0.001

Conclusion:

DTI and perfusion scan clearly differentiates between the tubercular and non-tubercular arthritis.

To cite this abstract, please use the following information:
Agarwal, Vikas, Awasthi, Rishi, Tripathi, Deepak, Agrawal, Vinita, Singh Rathore, Ram Kishore, Sahoo, Prativa, et al; Diffusion Tensor and Perfusion Magnetic Resonance Imaging Delineates Microstructural Changes of Inflammation and Differentiates Between Tuberculosis and Chronic Inflammatory Arthritis. [abstract]. Arthritis Rheum 2011;63 Suppl 10 :954
DOI:

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